Google, Facebook, Yahoo, eBay and graphics card maker NVIDIA have all come out in opposition to the US government's approach to tackling internet piracy, which the Hollywood movie studios claim is costing them millions every year.

The tech firms are primarily concerned about measures to 'throttle' or block websites accused of copyright piracy, arguing that this runs the risk of threatening the core principle of a free and open internet.

TIGA said today that online games developers are also concerned by the US legislation over fears that the community element of internet-based gaming could be "crushed".

Jagex, the creator of various browser-based MMORPG games such as Runescape and War of Legends, said that SOPA, if ultimately passed in the US, would risk eroding "freedom of speech, creativity and opinion sharing".

"Jagex is fervently opposed to the proposed Stop Online Piracy Act as it will essentially create a national censorship firewall for American internet users," said the firm's chief executive Mark Gerhard.

"Specifically this could crush the community element of online gaming and could result in a huge lack of freedom of speech, creativity and opinion sharing.

"Secondary to providing compelling games Jagex provides a social platform for our own community which could be hugely affected, negatively impacting on community sharing, forum activity, even in-game chat."

Under current US law, only the creators of copyright-infringing material can be sued by the copyright owners, but SOPA proposes extending the powers to any websites that carry the material.

This would mean that anyone using an online game, forum or games media website that posted material infringing copyright would potentially make the website they are using liable for a lawsuit, resulting in costly legal proceedings.

The proposed US legislation would also stop people from being able to share unauthorised screenshots and videos on gaming forums, which TIGA believe is "disproportionate" and also "potentially damaging" to online games businesses.

"The worry is that this legislation would expose online games businesses to damaging legal action, while inhibiting innovation and leading to over-caution online," said TIGA chief executive Dr Richard Wilson.

"Video game companies could have to spend time and money analysing the behaviour of their users. TIGA understands the need to clamp down on rogue websites - those which blatantly make money from piracy and therefore restrict the profit margins of developers and digital publishers - but it believes SOPA would be a sledgehammer cracking a nut."